Neuroscience of Intelligence

The Neuroscience of Intelligence

Several scientists have looked at the neural correlates of intelligence. Of course, since the concept is subjective and complicated, the task is a difficult one. Nonetheless, some interesting facts have been established.

For example, Narr et al. (2006) attest that there is a relationship between regional gray matter thickness and IQ (Intelligence Quotient) tests. As a brief aside, the brain is composed of gray matter and white matter. Gray matter represents neuronal cell bodies, while white matter consists of axons. Axons are myelinated, and myelin is a fatty substance that speeds transmission, which explains the color. Thus, the authors have examined the association, and found a positive correlation between gray and, to a lesser degree, white matter volumes and Full-Scale Intelligence Quotient (FSIQ). However, no such link was present in relation to cerebrospinal fluid quantities.

Spatial intelligence, as required by artists and designers, is one type of modality, according to Gardner’s multiple intelligences theory. Copyright © Megan Jorgensen (Elena)

Further, Jia et al (2011) used fMRI (functional Magnetic Resonance Imaging – a neuroimaging technique taking advantage of BOLD – or Blood Oxygen Level Dependent – changes to study the brain) to highlight neural correlates of numerical inductive reasoning. The researchers attest that there are two components to the process, namely identification and extrapolation. They report that the SPL (Superior Parietal Lobule) extending into the precuneus, and the left DLPFC (dorsolateral prefrontal cortex) were involved in both components. Brain anatomy is discussed in more detail elsewhere.

On the one hand, Gullick et al. (2010) suggest that individual differences in academic achievement in such areas as mathematics, may be caused by dissimilarities in working memory and intelligence. As a rule, the frontal and parietal lobes have been documented as processing numbers. On the other hand, in their study, symbolic number processing was associated with bilateral parietal, temporal and right frontal regions activity.

Additionally, Stout and colleagues (2011) wondered about the neuronal substrates of Early Stone Age toolmaking. Human evolution has correlated with brain expansion, and although there is obviously no prehistorical cortical imaging data, the group carried a positron emission tomography experiment in today’s day and age. The results portrayed enhanced activation of the ventral premotor and inferior parietal elements of the parietofrontal praxis circuits bilaterally, as well as famous Broca’s area in the right hemisphere, during advanced tool craftsmanship.

The brain has often been called the most complex object in the world. While much remains to be discovered, neuroscientists worldwide are relentlessly shedding light on the mysterious, physical workings of the mind. Finally, the reader is referred to other articles and videos examining the neural correlates of cognition, thought, memory, emotion, love, happiness, beauty and decision making.

In addition to these initial seven modalities (spatial, linguistic, logical-mathematical, bodily-kinesthetic, intrapersonal, interpersonal and musical), naturalistic and existential intelligences were later added to the list. Image: Copyright © Megan Jorgensen (Elena)

References:

• Gullick, M. M., Sprute, L. A. and Temple, E. (2010). Individual differences in working memory, non-verbal IQ and mathematics achievement and brain mechanisms associated with symbolic and non-symbolic number processing. Learning and Individual Differences: 1-11.
• Jia, X., Liang, P., Lu, J., Yang, Y., Zhong, N. and Li, K. (2011). Common and dissociable neural correlates associated with component processes of inductive reasoning. NeuroImage, 56: 2292-9.
• Narr, K. L., Woods, R. P., Thompson, P. M., Szeszko, P., Robinson, D., Dimtcheva, T., Gurbani, M., Toga, A. W. and Bilder, R. M. (2007). Relationships between IQ and regional cortical gray matter thickness in healthy adults. Cerebral Cortex, 17: 2164-71.
• Stout, D., Toth, N., Schick, K. and Chaminade, T. (2011). Neural correlates of Early Stone Age toolmaking: Technology, language and cognition in human evolution. Philosophical Transactions of the Royal Society, 363: 1939-49.